I also tried passing the parameters directly to httr as mentioned in this question: How can I POST a simple HTML form in R?, but the "submit" parameter did not accept the submit button either with backwards quotes (``), quotation marks, or without any quotes:

And I now see a nice 200 status code response instead of an error. Note that because the desired submit button appears to be the first submit button, we don't need to give it as an argument, but otherwise we'd just be giving it a a string (straight quotes, not back quotes).

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